Type: Motor neuron
In MoW: DDn
Male Wiring Project: DDn, DD03, DD04, DD05, DD06
In Wormbase: DDn, DD1, DD2, DD3, DD4, DD5,
DD6
Lineage: AB plppappap, AB prppappap
AB plppapppa, AB prppapppa
AB plppapppp, AB prppapppp
Location: Body; Ventral cord
Description: GABAergic inhibitory ventral cord motor neurons. DD's receive dyadic synapses from excitatory ventral cord motor neurons along with body wall muscles. The initial pattern of synapses made by DD neurons are presynaptic and inhibitory to ventral body wall muscles while being postsynaptic to neurons that activate dorsal body wall muscles. During late L1, after the birth of VD motor neurons, DD neurons change their synaptic pattern such that their dorsal branches become presynaptic and inhibitory to dorsal body wall muscles while their ventral branches become postsynaptic to excitatory neurons that synapse on ventral body wall muscles (White et al., 1978; Walthall et al., 1993). Hermaphrodites and males exhibit some differences in DDn connectivity.
Neurotransmitter:
Function: Sinusoidal body movement. DD's receive input from VA and VB neurons, and hence, are likely to be active during ventral muscle contractions. They form neuromuscular junctions dorsally that coordinately relax the dorsal muscles during ventral muscle contraction (Driscoll and Kaplan, 1997). D-type neurons may also regulate the wave amplitude of the sinusoidal movement since unc-25 and unc-30 mutants that lack functional D neurons generate rhythmic sinusoidal movement with a reduced amplitude (McIntire et al., 1993).
Receptor Expression: Express neuropeptide Y receptor like protein, NPR-1 (Coates and de Bono, 2002; Wang and Wadsworth, 2002). Suggested to express GABA-A/glycine receptor-like protein GGR-2 (Fujiwara et al., 1996). Express UNC-8, a DEG/ENaC family member homologous to subunits of a candidate mechanically gated ion channel (Tavernarakis et al., 1997).